The prevent invention relates to a system for preventing overheating of a clutch for an internal combustion engine.
A clutch such as friction clutches and electromagnetic clutches slips between slipping surfaces of the clutch, when the speed of the crankshaft of the engine is different from the speed of a driven shaft. The slip generates heat which elevates the temperature of the clutch. In the normal clutch operation, the amount of heat is negligible, but if the slipping continues for a considerable time, the clutch elements will be destroyed.
Describing overheating of the clutch, for example, with respect to the electromagnetic clutch for a vehicle, the electromagnetic clutch is so arranged that the clutch torque is controlled in dependency on the engine speed for achieving a smooth starting of the vehicle, even when starting on a steep hill in the upward direction, while allowing slipping in the clutch at an engine speed providing a clutch torque suitable for starting. However, if such a slipping condition continues for a long time, the clutch will overheat causing an impaired clutch operation.